Double-wall venturi steam fitting



March 13, 192s.

1,662,095 J. o. wooDsoME DOUBLE WALL VENTURI STEAM FITTING Filed Jan. sa. 1926 2 sheets-sheet 1T J. O. WOODSOME DOUBLE WALL VENTURI STEAM FITTING March 13, 192s. 1,662,995.

Filed Jan. 9. 1926 2 Sheets-Shee't 2 l It Patented Mar. 13, 1928. 'l

UNITED vSTATES J'OHNO. WOODSOME, OF NEWTON, MASSACHUSETTS.

DOUBLE-WALL VENTURI STEAM FITTING'.

Application v filed January This invention relates to a double Wall Venturi steam fitting, more particularly adapted for use in connection with a steam circulatingsystein for paper machine driers.

In my copending application Serial No. 2,868, tiled January 16, 1925, Irexplained the Construction, use and advantages of a simple Venturi type of steam fitting as applied to paper machines. My rpresent invention is an improvementv over my'former device in that my Venturi fitting is now provided with removable inner members, thus Vmaking replacement more easily accomplished Whether for the purpose of installing a new: member or a member` of diferentsize. Furthern'iore, in my present circulating system' I provide two. Venturi types of tittings, one in the steam inlet line to act as a circulator and; one in the exhaust line from the. driers toract as a separator'. In this Way 4I obtain amore rapid and positive circulation even `than heretofore.

It is therefore an object of this invention to provide an improved 4double Wall Venturi circulator especially. adapted tov effect a rapid and eflicient circulation ofr steam throughdriers and to afford positive suction means fortheremoval through a Venturi separator of. condensate, air` and noncondensz'rble gases from the vdriers -and for the separation of vsaid condensate, air and non-condensable gases fromthe steam. n

It is a further object of this invention to provide a steam circulating systemy for driers that'ivill materially increase the thcrmal eciency of thel driers fand which will therefore resultv in substantial economies-in the dryingprocess.

Other and furtherA important objects of this invention will be apparent from the disclosures in the specification andthe raccompanying drawings.

Thisinvention (in a preferred form) is illustrated in the drawings andyhereinafter more fully described.

On the drawings: f

Figure l is a fragmentary end view of a paper machine drier-.havingconnected therewith a steam circulating system employing my improved double Wall Venturi circulator and separator, with parts .in section.

Figure 2 is a side elevational vieu7 of the same, with parts in sect'ionf Figure 3 is a longitudinal sectional view showing the construction ofmy double Wall Venturi ycirculator;

9, 1926. Serial No. 80,230.'

Figure e is a longitudinal sectional view showing the construction of my double Wall Venturi separator.

As shown on the drawings: y The reference numeral l refers to a drum drier of the usual type found in paper making machines. The customary method of heating such a. drum is by introducing live steam thereinto through a hollow journal, the drum itself acting` as a condenser to condense a portion of the. steam. The condensed steam forms a film on the inside of the drum and will, if not removed, forma very effective insulating medium Whichacts to cut down the rate of transfer of hea-tthrough the drum shell to the paper in contaetthercivith. Accordingly it is very important to remove the condensate as quie-lily as. formed, or otherwise the thermal efficiency of the drier will `be greatly reduced, with consequent poor economics and With del# eterious effect on the quality of` paper made. 'lhe methods in common use nowv for removing the condensed steam from the ldrier are either the bucket or the siphon type system. My Venturi circulator and separator may be employed with either sys tem, but is here` shown in connection with a. condensate removal system of the Siphon .typer Y The drum l is provided at its rear end with a `hollen7 journal 2 supported in a suitable bearing 3 Whichin turn is mounted on a structural support 4. A driving gear 5 is secured to the journal 2 on the other side of the bearing 3 from the drying drum. A. self-adjusting oil less steam litting 6 is provided for the end of the journal 2 Which eX- tends beyond the gear 5. A siphon pipe 7 extends from a point near the bottom `of the drum l through the entire length of the hollow journal 2 and through the elbow of the steam fitting 6. The steam fitting 6, which is supported by an upright supporting member 6, is connected by a steam inlet pipe 8 to a steam supply header 9. In this steam inlet pipe 8 I connect at any suitable point a Venturi circulator l0 of my improved double wall type. Said eirculator 1 ()(Figure 3) comprises an outer casing ll having flanged ends 12 and 13 adapted to be secured respectively to a flanged ring ll on the pipe 8 and to a flanged conical section l5 forming an extension to the diffuser member of the circulator. Said section l5 is provided at its other end with aninternally threaded portion 16 into which is threaded a ni ple 17, which forms a part of thepipe 8. Said outer casing 11 may be cylindrical or may be slightly constrictedas shown, and is provided at its constricted portion with a side opening 1S threaded to receive a Suction pipe 19.

The Venturi circulator proper comprises a pair of conical shaped members 20 and 21, which l will call the diffuser and throat, respectively. The diffuser 2O is a relatively long member, slightly tapered to form a constricted opening or orifice 22, beyond which said member is larcd outwardly as at 23 for a. short distance. An annular flange 24 on the large end of the diffuser 20 is adapted to fit into a corresponding recess in the flange 13 and to be clamped therein between said flange 13 and the flange of the diffuser extension 15. Abutting lugs 25 and 26 are formed on the inside of the casing 11 and on the outside of the diffuser 20 to properly position the diffuser 2O within said casing. The throat 21 is similar in construction to the ditl'user 20 butis relatively shorter and of larger diameter at its big end and has a smaller eoiistricted portion 31. It is suitably held in place by means of a` flange 27 adapted to be clamped between the abutting flanged ends 12 and 14 and by means of positioning lugs 2S and 29. Said diffuser 20 and throat 21 are so positioned as to provide a gap 30 between their respective adjacent ends, said gap being centrally located of the opening 18 and in communication therewith.

It follows from the well known principles of a venturi that at the constricted portion 31 of the throat 21 the velocity of the Steam passing through will be greater` than that vot thesteam in the pipe 8.l The increased velocity'ot the steam as it issues from the throat 21 will therefore cause a certain amount of suction through the gap 30 and a reduced pressure in the suction line 19. Said suction line 19, however, is connected with a separator 32 in a steam exhaust line k33 forming a continuation ofthe Siphon 7.

The separator 32 (Figure 4) is similar in construction to that of the circulator 10, the main difference being in the dimensions of the Venturi parts 34 and 35. Said parts 34 and 35 are removable, as are the diffuser 20 and throat 21 of the Venturi circulator 10, and ai'e similarly spaced to form a gap 36. On one side of said gap 36 and slightly above the saine there is provided an air lvalve 37. The suction pipe 19 enters the separator on the other side of the air gap 36 and on a level therewith. A continuation of the exhaust or drain pipe 33 leads into a. return n header 38.'

The operation of my steam circulating system is substantially as follows. Steam under pressure enters the drier 1 from the supply header 9 through the pipe 8 and the Venturi circulator l0. In passing through the constiictcd orifice 31 of the throat 2l, the velocity of the steam is greatly increased, with the result that in passing across the gap 30 the steam creates suflicient vacuum in the suction pipe 19, separator 32 and siphon 7 to effect a rapid circulation through said pipe. separator and siphon. The condensed steam, air and non-eendensable gases, together with a certain amount ot' uncondensed steam from the drier drum are all drawn through the Siphon pipe y into the Venturi separator 32, where the air and non-condens able gases are separated out through the air valve 37. The condensate, be `anse of its greater momentum, passes straight through the Venturi members 34 and 35 into the drain pipe 33. Whatever uneondensed steam is sucked over into the Venturi separator 32, is drawn off through the suction pipe 19 by the suction action created at the orifice 31 of the throat 21 and is recirculated through the drier.

It will thus be apparent that my Venturi circulator cfiects a positive circulation of the steam through the drier and that my Venturi separator provides for the separation of the air, non-condensable gases and water of condensation from the live steam. The advantage of my system is evidenced by actual tests made with and without my Ven turi circulator and separator, wherein an increase in the etliciency of the drier of over 20% was obtained by using the same.

AOne important advantage of the double wall construction in the Venturi circulator and separator is that the size of the inner Venturi' members may be varied, using the same size outer casing. Furthermore, the inner members being removable, can be replaced when ,worn or corroded. As there are no moving parts, the amount of wear and tear is reduced to a minimum and is considerably less than would be the case wheremechanieal pumps of the piston or rotary type are used to effect circulation of steam through'the drier. As is obvious, the size 'and type of throat fitted to the sepa-- rator will influence to a great extent the efficiency obtained from the drier. In general, it has been found advisable to use separators with smaller throats on the driers at the dry end, gradually increasing the size of the throats on the separators toward the wet end of the paper machine. y

I am aware that many changes may be made, and numerous details of construction may he varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patentl granted hereon. otherwise than necessitated by the prior art.

I claim as my invention:

1. A steam circulating system for driers, comprising a steam inlet pipe into a drier,

a Venturi type of Iitting connected in said vvlipe, an exhaust pipe from said drier, a 7enturi type of fitting in said exhaust pipe and a connection between the eonstrieted portions of said fittings. Y

2. The combination with a paper making machine drier drum, of a steam supply pipe, a steam inlet pipe connecting the steam supply pipe with the interior of the drier druni, a drain line leading :from Within the drier drum, a Venturi oireulator in the steam inlet pipe and a Venturi separator in the drain line connected to said eireulator.

3. The `combination with a paper making machine drier drum, of a steam supply pipe, a steam inlet pipe conneeting said rsteam supply tank to the interior of the drier drum7 a drain line leading from Within the drier drum, Venturi type fittings in said inlet and drain lines, each of said fittings having a side opening, and a pipe secured 1n said openings or reeiroulatlng uneondensed steam.

1i. The combination with a paper making machine drier drum, of a steam supply pipe, a steam inlet pipe connecting said steam supply tank to the interior of the drier drum, a drain line leading from Within the drier drum, fenturi type fittings in said inlet and drain lines, each of said fittings JOHN O. WOODSOME. g 

